This invention relates to carriers for objects and more particularly to the easy identification and/or orientation of such carriers during manufacturing processes. The invention has particular relevance to the semiconductor industry.
In the semiconductor industry semiconductor chips such as microprocessors and the like are packaged on carriers called matrix trays. The matrix trays carry a number of semiconductor chips which are passed along a production line for assembly of completed circuit boards. The matrix trays are typically injection moulded plastics having a height of about 1 cm.
The trays carry technical information relevant to the tray, the chips carried or the process, such as temperature rating, part number, date code, etc. This technical information is usually embossed on the edge of the tray, which is typically about 1 cm high. As the trays flow through the production line the following inconveniences occur:
1. Difficulty in reading the embossed descriptions on tray surfaces, especially when they are stacked high. The printed information is not large enough due to the limited space on the edge of the tray. Also, the printed characters and numbers are the same colour as the tray""s surfaces so there is little contrast to aid in reading them.
2. Difficulty in identifying trays that house good chips as against those used to store rejected ones. When bad chips are identified and segregated by the machines during the assembly process, they are separated but housed onto the same type of trays. The same type of trays are needed as they are specifically designed to house a particular size and family type of chips.
3. Difficulty in identifying different types of chips within a family that use the same body dimension of the tray. As different machines are required for handling a particular type of chip within a family, the use of the common tray makes it difficult to identify the correct chips for each machine.
4. Difficulty in identifying the correct tray orientation during the machine loading. The tray must be loaded manually with a specific orientation. Although present trays come with a tiny corner chamfer on one of its corners, it is not conspicuous enough to ensure correct loading onto the machine.
It has been proposed to use coloured stickers to help differentiate certain trays from others. However, the stickers need to be removed before delivery to customers and this sometimes leaves adhesive material on the tray.
In an attempt to overcome at least some of the disadvantages of existing matrix trays, in one broad form the invention provides a carrier for supporting one or more articles, the carrier including:
a main body having at least one engagement means; and
at least one indicator means for engagement with the engagement means, the or each at least one indicator means including means to provide information visually or tactually to an observer regarding the carrier or the articles supported thereon or both.
In a preferred form, the invention is a semi conductor matrix tray having at least one removable indicator means. The indicator means may be positioned prominently along one side of the tray and be assigned different colours, shapes or numbers to indicate technical information. Preferably the colours used for the indicator means contrast with the colour of the tray adjacent the indicator means.
Preferably the indicator means slides into a receptacle on one side of the tray. Preferably the receptacle and the indicator means are shaped so that only one orientation of the indicator means relative to the receptacle is allowed. The indicator means may have a receptacle which receives a protrusion on the tray.
Preferably the indicator means includes a first part which engages in or on the edge of the tray and a second part mounted on the first part. The first part may then be made of one of a series of different colours whilst the second part may also be made of one of a series of different colours and/or shape.
One or both of the first and second parts may be of a contrasting colour to the tray or the same colour. The second part may partially or totally obscure the first part when the indicator is mounted on the tray.
More than one indicator may be used on the one tray.
The invention will be more easily understood from the following non limiting description of a preferred embodiment and the drawings in which: